Tokens and token handling devices

ABSTRACT

A token handling device transmits, using an electromagnetic carrier, data, clock pulses and power to a token. The token transmits data by varying the degree of absorbtion of the carrier in synchronism with the clock pulses. These data transmissions are detected by a receiver in the token handling device, the sensitivity of which is adjusted each time a token is received. The token could be used in transactions in place of coins, or alternatively could be used for identification in other areas. Data stored by the token could be used to change the way in which the token handling device operates. The token handling device may for example form a vending machine, and the token could be used to alter the pricing of goods vended thereby. The token handling device may be combined with a coin validator, in which case there is preferably a common path from an entrance slot for carrying both the tokens and the coins to appropriate testing apparatus.

This invention relates to tokens and token handling devices.

The invention is particularly, although not exclusively, useful in thefield of vending machines, gaming machines, amusement machines, paytelephones, change-giving apparatus and like machines which dispensesomething of value or perform a service or function in exchange formoney received from the user. Such machines will for convenience bereferred to herein as coin operated machines. These machines generallyhandle a large volume of coins, which means that the machines need tohave a large storage space for the coins, that the coins need to beregularly collected and transported to a central location, and that theythen need to be counted and delivered to a bank. This procedure isinconvenient and expensive for the owner of the machine. In addition,the user has to have coins available in order to use the machine, andwould therefore need to carry an inconveniently large number of coins ifhe wished to use the machine often. He would have to have the correctdenominations of coins available unless the machine was of thechange-giving type, and in the latter case carrying the change aroundwould be inconvenient.

Some of the machines referred to above, for example gaming machines,have been capable of handling special tokens in addition to genuinecoins. However these tokens have generally been treated in much the sameway as genuine coins.

The present invention is concerned with arrangements which cansubstantially mitigate the disadvantages referred to above by arrangingfor the machines to be able to handle, in place of or preferably inaddition to genuine coins, data-storing tokens which can be used toauthorise transactions of different values, and which are preferablyreturned by the machine so that the tokens can be repeatedly used. Twotypes of system could be used: a debit system in which a user makes aninitial payment for a token which stores therein data representing itsvalue, the machine being operable to alter this stored data upon use ofthe token so as to reduce the value by an amount corresponding to thevalue of the transaction; and a credit system in which the token storesdata representing an account of the user, the machine being operableupon use of the token to note this account data so that the account canthen be debited by an amount corresponding to the value of thetransaction. In the latter case, the machine could be connected on-lineto a central station which keeps the account information, or could storeinformation which is regularly collected by means of data storagemodules.

Allowing the user to operate the machine using a "debit" or "credit"token effectively avoids the problems referred to above relating to thehandling and carrying of large numbers of coins.

It will be appreciated, however, that aspects of the invention havevalue in other fields. For example, the invention is also useful in thefield of identification tags, wherein for example data-storing tokenscould be used with automatic equipment for gaining access to areasrestricted to authorised personnel.

A first specific aspect of the invention relates to a device whichhandles both coins and tokens storing data which can be determined uponcommunication between the device and the token, the device having acommon path for receiving the coins and the tokens and for deliveringthem to testing apparatus for validating the coins and communicatingwith the tokens.

The use of a common path has the advantage that the user can operate themachine using tokens in the same way as the machine is operated usingcoins, e.g. by inserting tokens and coins through the same slot. Thisfeature also has the substantial advantage that, because it is notnecessary to provide a separate entrance slot and path for the tokens,modifying the vast number of existing machines already in use so thatthey can additionally handle tokens is rendered much more simple.

The testing apparatus is preferably arranged to have two separatetesting stations, one for validating the coins and the other forcommunicating with the tokens, the arrangement being such that onlythose items which are rejected by the first testing station aredelivered to the second testing station.

It is preferred that the coin validator be the first testing station.This permits existing coin operated machines to be adapted to handletokens without requiring any physical modification to the coin handlingmechanism up to and including the coin validator. Instead, it is merelynecessary to install the test station for the tokens along the pathtaken by items rejected by the coin validator. This feature isparticularly useful in that it is very common for coin mechanismsincorporating a coin validator and a separator for separating rejecteditems and genuine coins to form a unit, and for the same type of unit tobe installed in different kinds of coin operated machines. In thesecircumstances, the coin path leading to the validator may varysubstantially depending upon the machine in which the coin mechanism isinstalled. If the token interrogation station were to be installed infront of the coin validator, in some cases there may be insufficientroom in the vending machine to permit this modification withoutsubstantially changing the configuration of the coin mechanism itself.This is avoided in the preferred embodiment by installing the tokentesting station within the unit and along the reject path.

It is envisaged that in most public installations, the majority of itemsinserted into the device will be genuine coins, and that very few itemswhich are neither genuine coins nor tokens will be inserted. Thus, byarranging for coin validation to occur first, the majority of itemsdelivered to each testing station will be appropriate for that station,so that the device operates in an efficient manner.

The device preferably has means for temporarily retaining the tokenswithin the device until a transaction is completed. If the token is adebit token, this feature is desired to enable the value stored in thetoken to be altered by an amount corresponding to the value of thetransaction before being returned to the user. If the token is a credittoken, this feature is desirable, particularly in "multi-vend" machineswhich can be operated a number of times in succession without requiringthe user repeatedly to insert coins or tokens, because retrieving thetoken would be a convenient way of signifying the end of a transactionor a series of transactions. A credit token could instead be returnedimmediately to the user after interrogation, but this means that theuser would then have to perform some operation to advise the machinewhen his transactions are completed, and if he were to forget to do thisthe values of subsequent transactions carried out by other users wouldbe deducted from his account.

The holding station at which the token is temporarily retained ispreferably, like the token testing station, disposed after the validatorand more preferably after separation by an accept/reject gate so thatthe station receives only those items which are rejected by thevalidator. In a particularly convenient embodiment, the token testingstation and holding station are combined. This has the advantage thatcommunication with the token can be carried out after the token has beenhalted at the holding station.

The device preferably also has means for updating or otherwise alteringthe data in the token, or introducing new data into the token, which inthe debit system would be used to alter the token's value after atransaction has been carried out. The means for accomplishing this ispreferably also disposed at the holding station, although in analternative embodiment it could be disposed downstream of the holdingstation so as to update the data during the token's exit from themachine.

Preferably, means for obtaining data from the tokens and means forupdating information in the tokens are both disposed at the holdingstation. The two functions may be performed using common components.

According to a second specific aspect of the invention, a token storingalterable data which can be determined by communication with the tokenis substantially coin-shaped and sized. The token is such that it canenter and pass through a standard coin handling mechanism. This has anumber of advantages. It means that modifying existing coin operatedmachines so that they can additionally handle the tokens is renderedmuch easier, because it merely involves fitting a means forcommunicating with the token to otherwise fairly standard equipment. Forexample, as described above, a testing station can be disposed along areject path of the mechanism, so that the token passes through thevalidator, is rejected and then reaches the testing station. This aspectof the invention also has the advantage that even if machines areintended to be used only with tokens, and not with genuine coins, it isnevertheless possible to use standard coin handling mechanisms andtechniques.

The token may contain its own power supply, but preferably is powered byenergy transmitted by the token handling device.

The tokens used in the various aspects of the present invention arepreferably arranged so that they and the device can communicate in a"contactless" manner. Various techniques can be used. For example, verylow frequency radio transmission can be used to obtain data from, and ifdesired to pass data to, the token. British Patent Specifications Nos.1,599,120 and 2,077,556A describe radio techniques for interrogation.Other methods, e.g. optical techniques, could alternatively be used.

One alternative technique, which is considered particularlyadvantageous, forms the subject of a third aspect of the presentinvention. In accordance with this aspect, a token handling device,referred to also as a token interrogator, has means for communicatingwith a token by determining how an electromagnetic field is absorbed bythe token. The invention also extends to a token suitable for use withsuch a device. The token preferably has a field-absorbing circuit whichcan be controlled so as to alter the degree or nature of the absorption.

In one embodiment described herein, this is a resonant circuit whoseresonant frequency can be switched between at least two values. Thedevice may communicate with the token by generating an electromagneticfield of different frequencies, and more preferably of acontinuously-swept frequency. The device determines data stored in thetoken in accordance with the frequencies at which absorption of thefield occurs. Preferably, the device determines the data in response tochanges in the absorption frequency, so that it operates substantiallyindependently of the specific resonance frequencies of the resonantcircuit.

An alternative, preferred arrangement is also described herein. In thisarrangement, the token is powered by an electromagnetic signaltransmitted by the interrogator (preferably of a frequency around 100kHz). The same signal as is used for transmitting power is also used forcommunication between the token and the interrogator. Data iscommunicated to the token by selectively interrupting the powertransmissions for brief periods. The token has power storing means sothat these interruptions do not interfere with its operation. The tokensends data to the interrogator by selectively coupling a low impedanceacross its receiving antenna. This alters the degree of energyabsorption, which can be sensed by the interrogator. The datatransmissions are preferably made at predetermined times, and tofacilitate this a clock signal is preferably used. Preferably, theinterrogator transmits clock pulses in the same way as data pulses, andthese clock pulses are used both for transmissions to the token andtransmissions from the token.

In addition, in this arrangement, the token contains a non-volatilereadable and writable memory (preferably an EAROM). This is desirablyused for storing operational data such as the token value, but also hasanother use. In particular, it may be desirable in many circumstances toterminate the power transmission to the token before all the operationsinvolving the token have been completed. This for example may be usefulfor reducing power consumption when the token is used in a pay phoneinstallation; the token may be interrogated when first inserted to checkits validity, whereupon the power is cut off for the duration of thetelephone call and thereafter reapplied to allow the token value to bereduced by an amount corresponding to the cost of the telephone call.Thus, on powering-up of the token, either of two sequences of operationsof the token could be required (i.e. transmission of data to theinterrogator, or receipt of data from the interrogator). Thenon-volatile memory in the token can be used to store a flag whichindicates which part of the complete cycle of operations the token isin, and which is used to determine what actions are taken by the tokenupon powering-up. This arrangement embodies a number of furtherindependently inventive aspects, amongst which are:

(a) A system comprising a token which receives power from an antenna andsends data by altering the impedance across the antenna (preferably byshorting-out or at least connecting a very low impedance across theantenna).

(b) A token and interrogator between which two-way communication can beestablished using the same carrier signal, which signal originates fromthe interrogator (and preferably transmits power and/or clock pulses tothe token).

(c) A token and interrogator between which two-way communication can beestablished, communication in both directions being synchronized withclock pulses transmitted by the interrogator.

(d) A system comprising a token powered by energy received from theinterrogator, the token having a non-volatile writable memory and beingarranged to perform, following power-up, one of a plurality of sequencesof operations dependent upon flag data stored in the memory, at leastone of those sequences resulting in a change in that flag data.

It will be appreciated that these aspects of the invention reside in thetoken and interrogator individually, as well as the combination thereof.

The token handling device may have transmission and reception coils fortransmitting and receiving the signal which is selectively absorbed bythe token. Alternatively, a single coil could be used for both thesepurposes.

In accordance with a still further aspect of the invention a tokenhandling device is arranged for automatically altering its sensitivityto received transmissions in the presence of a token, and preferablyeach time a new token is received by the handling device. Thetransmission carrier could originate at the token, but this aspect isparticularly useful when the token transmits data by altering the degreeby which it absorbs a carrier transmitted from a different source, andalso when the token is powered by received electromagnetic energy,because in those circumstances the signals received by the tokenhandling device may vary due to slight differences in the tokens, orslightly different positions of the tokens. This can be compensated forby adapting the receiver sensitivity to ensure that changes inabsorption of the carrier transmitted by the token handling device arecorrectly received by the token handling device.

The device is preferably able to communicate with the token irrespectiveof the particular orientation of the token.

According to a further specific aspect of the invention, there isprovided a token handling device which performs operations in accordancewith operational data stored in the device, and which is capable ofcommunicating with a token in order to determine token data storedthereby, the device being operable to enter a first mode or a secondmode in dependence upon the token data, the device being operable in thefirst mode to perform a said operation, and in the second mode to alterthe operational data in a manner dependent upon said token data.

It is envisaged that the device would normally be caused by enteredtokens to perform operations (such as permitting access to certainareas, or in the case of vending machines and the like vending a productor performing a service), but could also have its operational parametersaltered by entering a special token storing predetermined data. Thiswould be useful for example if a vending machine owner wished to changethe pricing data stored in his vending machines. He would have aspecially encoded token which would cause this to occur upon insertioninto the vending machine, so that the pricing change could be achievedas easily, and using the same electronic components, as when using atoken to purchase a product from the machine.

In the field of identification tokens, which may store a special codewhich when read out by the device permits access to a particular area,it may be desired for security reasons to change the code whichauthorises access. This could be achieved very easily by using aspecially encoded token which stores data such as to cause the device toenter the second mode, in which information in the token is used tochange a stored parameter so that in future the device will recognise adifferent security code as being appropriate for authorising access.

According to another specific aspect of the invention, there is provideda token handling device operable to receive and communicate with tokensin order to determine data stored thereby, and operable to perform atransaction and to alter the data stored by the token in accordance witha predetermined value associated with the transaction, the device beingoperable before performing the transaction to carry out a security coderecognition operation to determine whether the token stores a securitycode which is appropriate to that machine, and to carry out thetransaction only if the token stores such an appropriate security code.

Thus, vending machines, and like machines for dispensing products orperforming services, can be designed so that they will accept tokensissued by a particular company, for example that owning the vendingmachines, but will not accept tokens issued by other companies, whichtokens may be identical except for the security code stored therein. Inthis way, an owner of a chain of vending machines can ensure that he ispaid for all the tokens used to obtain products from his machines.

Preferably, the token handling device itself must store a security codewhich is appropriate for the token in order for transactions to becarried out. In this way, it can be ensured that a company's tokens willnot have their values altered in an unauthorised manner by insertioninto another company's token handling device.

The token handling device may be arranged additionally to handle genuinecoins.

In a preferred embodiment of the invention, aspects described above arecombined to produce a token handling system of substantial advantage andutility.

Arrangements embodying the invention will now be described by way ofexample with reference to the accompanying drawings, in which:

FIG. 1 is a schematic view of a coin and token handling device accordingto the present invention;

FIG. 2 shows a token in a testing station of the device of FIG. 1;

FIG. 3 is a schematic block diagram of the circuitry of the token andthe testing station in a first arrangement;

FIGS. 4(a) and (b) are waveform diagrams for illustrating the operationof the circuitry of FIG. 3;

FIG. 5 is a block diagram showing the token handling device and token ina second arrangement;

FIG. 6 is a circuit diagram of a receiver of the token handling deviceof FIG. 5;

FIG. 7 is a diagram of the circuitry of the token of FIG. 5; and

FIG. 8 shows waveforms of signals received by the receiver of the tokenhandling device of FIG. 5.

Referring to FIG. 1, the coin and token handling apparatus 2 includes acoin validator 4 for receiving coins and tokens as indicated at 6travelling along a common path 7 from an entrance slot (not shown).During the passage of the coins and tokens 6 along a path 8 in thevalidator 4, test operations are carried out to determine whether avalid coin has been inserted, and if so the denomination of the coin.These tests are standard ones, and may for example be inductive tests.

Acceptable coins then enter a coin separator 10, which has a number ofgates (not shown) controlled by the circuitry of the device forselectively diverting the coins from a main path 12 into any of a numberof further paths 14, 16 and 18, or allowing the coins to proceed alongthe path 12 to a path 20 leading to a cashbox. If the item tested in thevalidator 4 is not determined to be an acceptable coin, it is deliveredto a reject path 30 instead of continuing through the separator 10.

Each of the paths 14, 16 and 18 leads to a respective one of three coincontainers 22, 24 and 26. Each of these containers is arranged to storea vertical stack of coins of a particular denomination. A dispenserindicated schematically at 28 is operable to dispense coins from thecontainers when change is to be given by the apparatus.

Whenever a validator recognises an acceptable coin, a credit count isincremented by an amount corresponding to the value of the coin. Whensufficient credit has been accumulated, the device 2 produces a signalindicative of this. For example, in a preferred embodiment the device 2is installed in a vending machine (not shown), and the signal willindicate to the vending apparatus that a user may initiate the vendingof a product. The apparatus may be arranged to operate such thatproducts can be repeatedly vended until the credit count drops to alevel below the lowest of the prices of the products which the machinevends.

At any stage, the user may operate an "ESCROW" button, which terminatesthe transaction or series of transactions, and initiates the delivery ofchange of a value corresponding to the remainder of the accumulatedcredit, which credit is then cleared.

The arrangement described so far is quite conventional, and the detailsof particular structures suitable for accomplishing these functions willtherefore not be described.

The device of FIG. 1 has, in addition to these structures, a tokentesting or interrogation station 32, shown in more detail in FIG. 2.This station 32 is situated along the reject path 30 so that allrejected items are delivered to the station 32 before being delivered toa reject tray for retrieval by the user.

Referring to FIG. 2, the reject path 30 extends between a rear wall 34,a front wall which is not shown in FIG. 2 to permit the interior of theinterrogation station to be seen, and sidewalls 36 and 38. The rear wall34 has an aperture 40 so that a gate 42 can be selectively thrust intoand withdrawn from the path 30 by a solenoid 44.

Normally, the gate 42 is located in the path 30 so that all rejecteditems are stopped at the interrogation station 32. Each item isinterrogated, and if it is found not to be a token, the gate 42 iswithdrawn so that the item can proceed to the reject tray.

If the item is a token, it is held by the gate 42 at the interrogationstation 32 until the completion of the transaction or series oftransactions carried out by the user, following which the gate 42 iswithdrawn so that the token is returned to the user.

FIG. 2 shows a token 50 of a preferred embodiment of the invention,which is for use with debit systems and which therefore stores datarepresenting a particular value, which value is decremented after atransaction or a series of transactions has been carried out and beforethe token 50 is returned to the user.

FIG. 3 shows one example of the type of circuitry that can be used forthe token and the interrogation station. It will be appreciated thatmany other types of circuit could alternatively be used.

The interrogation station 32 has transmission and reception coils 52 and54, respectively. The transmission coil 52 is driven by a drive circuit56 which is operated in response to a signal derived from amicroprocessor 58. The microprocessor 58 also receives, via an inputcircuit 60, and processes signals from the reception coil 54, anddelivers signals to the main data bus 62 of the control circuit of thecoin handling mechanism. The data bus 62, input circuit 60 and drivecircuit 56 are connected to the microprocessor 58 via a multiplexingcircuit 64 which communicates with the microprocessor 58 via a data bus66, an address bus 68, and a read/write signal path 70. Themicroprocessor 58 controls the reading of data from, and delivering ofdata to, the token 50, and also communicates with the main coinmechanism circuitry so as to send the token value to this circuitry andto receive therefrom the remaining value after a transaction or seriesof transactions has been carried out.

The main coin mechanism circuitry may be of per se known form, such asthat described in published U.K. patent specification No. 2,110,862A. Inan alternative arrangement, the main prccessor of the coin mechanismcircuitry could be used to control the interrogation station directly,so that the additional microprocessor 58 would not be required.

In order to interrogate the token 50, the microprocessor 58 causes thetransmitter drive circuit 56 to drive the coil 52. The circuit 56 is soarranged that the output frequency used to drive the coil 52 sweeps froma low value to a high value each time the circuit 56 is operated. Theoutput frequency is shown in FIG. 4(a).

The token 50 includes a circuit generally indicated at 72 forselectively absorbing the energy transmitted by the coil 52. In thisparticular case, the circuit 72 is a resonant circuit including a coil74 and a parallel-connected capacitor 76. A further parallel-connectedcapacitor 78 can be switched in and out of circuit using a semiconductorswitch 80 in order to vary the resonance frequency of the circuit 72.

The energy transmitted by the transmission coil 52 is picked up by thereception coil 54, and the signal from this coil 54 is delivered to acomparator in the input circuit 60 for amplitude-detection purposes. Thesignal generated by the input circuit 60 is shown in FIG. 4(b ). It willbe noted that each time the frequency of the signal delivered to thetransmission coil 52 is swept, there is a point at which the energy isstrongly absorbed by the resonant circuit 72, so that a short pulse isproduced in the signal generated by the input circuit 60. The precisetime, within each frequency sweep, at which this pulse is produced isdependent upon the resonance frequency of the circuit 72, and cantherefore be altered by operation of the switch 80.

Transmission of data from the token 50 to the interrogation station 32is achieved by selective operation of the switch 80, for example suchthat a data bit "1" is represented by the absorption frequency when theswitch is closed, and a data bit "0" is represented by the absorptionfrequency when the switch is open.

This data can be detected by the microprocessor 58 in a variety of ways.For example, the microprocessor could be arranged to note when theinterval between the pulses received from the circuit 60 alters from avalue P1 (see FIG. 4(b)), which is determined by the rate at which thedrive circuit 56 is operated, to a value P2, which occurs when theresonance frequency has just been altered from its low value to its highvalue, or to a value P3, which occurs when the resonance frequency hasjust been altered from its high value to its low value.

Alternatively, the microprocessor could be arranged so that each time atoken is received, the time t1 (see FIG. 4(b)) from the start of thefrequency sweep to the time at which the circuit 60 produces a pulse ismeasured. During future frequency sweeps, the resonance frequency isdetermined to be low if the time taken for a pulse to be generated issubstantially equal to t1, and is determined to be high if the time is asignificantly greater value t2.

Neither of these methods relies upon the resonance frequency havingspecific values, so that large tolerances are permitted in the tokencircuitry.

Data is transmitted to the token 50 by amplitude-modulating the signalapplied to the transmission coil 52. The amplitude modulated signal caneither have a varying frequency, as in FIG. 4(a), or may simply have asingle frequency, for example located at the midpoint of the frequencysweep.

The signal is picked up by the resonant circuit 72, which has an outputconnected to a detection circuit 82. The circuit 82 is operable toderive from the received waveform the data transmitted by theinterrogation station 32.

The circuit 82 can detect predetermined codes which are transmitted bythe station 32. Detection signals indicative of these codes aredelivered to a control circuit 84. The detection circuit 82 can alsodetect data intended for storage in the token 50. This data is deliveredto a memory circuit 86.

In the present embodiment, the memory circuit 86 is a recirculatingshift register, the contents of which are shifted back into the registeras they are read out.

The control circuit 84 can cause data to be read out of the memorycircuit 86 and delivered to a transmission circuit 88. The controlcircuit 84 causes the transmission circuit 88 selectively to operate theswitch 80 in accordance with the data from the memory circuit 86, sothat the data is sent to the interrogation station 32.

The operation of the circuitry is as follows. When a token has beenreceived in the interrogation station, the drive circuit 56 is operated.This is detected by the token 50, which then sends to the station 32 apredetermined code which represents a request for the interrogationstation 32 to transmit a security code which the microprocessor 58stores.

This station security code is checked by the detection circuit 82, andfurther operations are permitted only if the station security code issuitable for that token. This procedure, which is optional, is done toensure that any subsequent alteration of the data in the token onlytakes place if the machine containing the interrogation station 32 is anappropriate one, for example one owned by a particular company. Thestation security code recognition operation could for example be carriedout by the circuit 82 determining whether the code matches a numberstored in the memory circuit 86 and received therefrom on line 90; thiswbuld enable tokens having the same circuits to be made suitable fordifferent machines simply by altering the contents of the memory circuit86.

Assuming that the station security code is appropriate for that token,the token then sends to the interrogation station 32 a token securitycode stored in the memory circuit 86. The microprocessor 58 determineswhether this token security code is appropriate for that machine, andonly permits subsequent transactions if the code is appropriate. Thisensures that the machine cannot be operated by insertion of tokenssupplied by unauthorised companies.

It will be noted that the token security code is transmitted only if thestation security code has been found to be appropriate. This improvesthe security of the system, as it renders it difficult for unauthorisedpeople to determine the token security code.

After the security code recognition operations, the token 50 proceeds totransmit a token value stored in the memory circuit 86. This could, ifdesired, be carried out only after the interrogation station 32 hasfirst acknowledged that the token security code is appropriate.

The microprocessor 58 then sends signals to cause the credit count to beincremented by the token value. The user is then permitted to carry outtransactions in the same manner as if the credit count had beenincremented by the insertion of coins.

After the completion of the transaction or series of transactions, theuser operates an ESCROW button 300. The device responds to this bydelivering to the microprocessor 58 data representing the remainingcredit. The interrogation station 32 then transmits this data to thetoken 50. The detection circuit 82 recognises a special code which hasbeen added to the transmitted data, and this code causes the controlcircuit 84 to shift into the memory circuit 86 data from the detectioncircuit 82 representing the remaining credit. This data replaces thepreviously-stored token value. The token 50 then acknowledges receipt ofthe data, following which the device causes the retraction of the gate42 and thus permits the token 50 to be returned to the user.

Tokens can be used with the device for a number of supplementarypurposes. For example, by inserting in the memory circuit 86 of a tokena special code in place of or in addition to the token security code,the microprocessor 58 can be caused, upon detecting this code, to entera special mode. In this mode, the microprocessor 58 extracts from thetoken 50 data which is then sent to the coin mechanism circuitry toalter a list of prices stored therein. This is a convenient way ofhandling changes in the price of products vended by the machine.

In a similar fashion, the microprocessor 58 can be caused to enter afurther mode used to change the security code which the microprocessor58 stores, so that in future different security codes would berecognised as appropriate for use with that device. A convenient way ofachieving this latter function would be for the microprocessor to enterthe further mode on receiving a first token storing the special code,but to wait for receipt of a second token before actually changing itsstored code. On receiving the second token, the security code stored inthe microprocessor 58 is replaced by that stored in the token. Thisarrangement has particular value when first installing machines, becauseit allows all machines to be initialised by using the same token,following which each machine will be adapted for use with a particularcompany's tokens in response to receiving one of those tokens.

Tokens can also be used for collecting data from the device. In thiscase a further predetermined code is stored in the memory circuit 86,and this is recognised by the microprocessor 58 as an authorisation totransfer into the token 50 the data which is to be collected. This couldfor example be audit data relating to operations which have been carriedout by the machine in which the device is installed.

Once the value of a debit token 50 has been reduced to zero, the tokencan, upon payment, have its original value re-inserted into its memorycircuit 86. This can be accomplished using a machine which is similar instructure to the interrogation station 32. In this case, however, themicroprocessor 58 would be arranged to deliver to the token 50 a furtherpredetermined value, which for security purposes would be kept secret.This further value would be recognised by the detection circuit 82 andwould cause subsequent data to be entered into the memory circuit 86 asthe token value. The detection circuit 82 is arranged so that increasedtoken values can only be inserted into the memory circuit 86 when thisspecial code has been received, although of course it will permitdecreased values to be entered in other circumstances.

In the arrangement described above, the token 50 is always returned tothe user after a transaction or a series of transactions has beencarried out. In an alternative embodiment, a gate is provided forselectively directing tokens from the interrogation station 32 either tothe reject tray 301 or to a storage box 302. Under normal circumstancesthe token is returned to the user. However, if the token value decreasesto zero, in a debit system, or if the stored account number in a credittoken is invalid, the token can instead be retained in the storage boxinside the machine.

Interrogation of the token and insertion of data therein is carried outin the above arrangement while the token is held at the interrogationstation 32. Alternatively, interrogation could take place as the tokenpasses through the coin validator 4. Indeed, interrogation could becarried out using components which are also used for coin validation,e.g. an inductive coil. In this case, the gate 42 can be arranged to benormally open so that all items other than valid tokens which arerejected by the coin validator 8 are delivered straight to the rejecttray.

It will be noted that the token 50 operates correctly irrespective ofits specific orientation within the interrogation station 32.

In the above embodiment, the input circuit 60 produces a two-leveloutput dependent upon the amplitude of the signal received by the coil54. This signal is then processed by the microprocessor 58. In analternative embodiment, the circuit 60 could contain for example a phaselocked loop or a monostable circuit for processing the signal from thecoil 54 in order that it may deliver to the microprocessor 58 a digitalsignal representing the data transmitted by the token 50.

The arrangement described above involves a token which communicatesusing inductive techniques, and preferably using a transmissionfrequency in the region of about 10 MHz to 100 MHz.

It will of course be appreciated that other techniques could be usedwithout requiring major modification of the circuitry. Low frequencyradio techniques could be used, or alternatively optical communicationtechniques.

FIGS. 5 to 8 illustrate a modified version of the circuitry describedabove in connection with FIGS. 3 and 4. Although these will be describedas separate embodiments, it will of course be appreciated thatindividual features described in connection with FIGS. 3 and 4 can beused in the embodiment of FIGS. 5 to 8, and vice versa. Referring toFIG. 5, the token handling device 100 comprises a transmitter drivecircuit 102 coupled to a transmitting antenna 104. The token 106 is, inuse, disposed between the transmitting antenna 104 and a receivingantenna 108. A receiver circuit 110 is connected to the receivingantenna 108.

A microprocessor 112 has an output line 114 for controlling thetransmitter drive circuit 102, three output lines 116 which control thesensitivity of the receiver circuit 110 as will be described, and aninput line 118 for receiving data from the receiver circuit 110. Thelines 114, 116 and 118 can be connected to the microprocessor 112 viaappropriate interface circuitry. The microprocessor 112 is alsoconnected to ROM, RAM and non-volatile writable memory circuits 120,122, and 124, respectively. The non-volatile memory circuit 124 ispreferably an EAROM.

The circuitry of the token 106 is shown in FIG. 7. The token has anantenna 130 which is connected via a diode 132 to a power storagecapacitor 134. The energy transmitted by the antenna 104 is half-waverectified by the diode 132 and stored by the capacitor 134, the voltageacross which is used to power the circuitry of the token 106. Thereceived carrier is also delivered to a diode 136 which is used for a.m.demodulation purposes. Interruptions in the transmitted carrier resultin pulses at the output of diode 136 which are delivered to a Schmittinverter 138, the output of which is connected to a latch 140. The latch140 can be read and cleared by a microprocessor 142 which has ROM, RAMand non-volatile (preferably EAROM) memory circuits 144, 146 and 148,respectively. The data is delivered to the microprocessor on line 150and a clear pulse is delivered to the latch on line 152.

The microprocessor 142 has an additional output line 154 which cancontrol an analog switch 156. When the switch is turned on, theterminals of the antenna 130 are shorted via a diode 158.

The lines 150, 152 and 154 would normally be connected to themicroprocessor 142 via appropriate interface circuitry (not shown).

In use of this embodiment, the token handling device is arranged, uponreceipt of a token 106, to cause the transmitting antenna 104 to starttransmitting a carrier wave at a frequency of the order of magnitude of100 kHz. Some of the transmitted energy will be picked up by the antenna130 in the token 106 and used to power-up the token. Some of theremaining energy will be picked up by the receiving antenna 108.

The transmitter drive circuit 102 is so controlled as to produceinterruptions in the carrier transmission. The interruptions are atregular intervals (say every 1 ms), and each lasts for, say, 3 carriercycles. They are sufficiently short that the voltage stored across thecapacitor 134 in the token 106 does not drop to an extent which wouldresult in interference with the operation of the token circuitry.

The microprocessor 112 in the token handling device then adjusts thesensitivity of the receiver circuitry 110 using the lines 116 until themicroprocessor receives on line 118 clearly defined pulses as shown inFIG. 8(a), which correspond to the interruptions in the transmittedcarrier.

Adjusting receiving sensitivity in this way should be sufficient toensure that shorting of the antenna 130 in the token 106, which resultsin a change in the amount of absorbed energy, will result in detectablepulses in the output of the receiving antenna 108. If desired, however,the system could be arranged so that receiver sensitivity is adjusted inresponse to actual operation of the switch 156 in the token 106 toensure that the resulting pulses are detectable.

Once the receiver sensitivity has been adjusted, the token handlingdevice starts to communicate with the token. To do this, alternatepulses 200 in the carrier wave as shown in FIG. 8(a) are used as clockpulses, while the intervening pulses 202 are used as data pulses. A datavalue of zero is signified by an interruption in the carrier andconsequently a pulse 202, and a data value of 1 is signified by nointerruption of the carrier, which will result in a missing pulse 202.

In the token 106, the microprocessor 142 repeatedly checks for a pulsein the latch 140, and upon detecting the pulse clears the latch. Theperiod between successive pulses is measured and stored. This measuredperiod allows the microprocessor 142 to calculate a "window" periodwithin which the next pulse is expected.

Data transmissions to the token are always initiated by data value of 1.Accordingly, the microprocessor 142 detects the first time that a pulsedoes not appear in the latch 140 within the expected period. At thattime, the token is able to determine which of the pulses in thesucceeding train are clock pulses 200 and which are data pulses 202.

The above description outlines how data is transmitted to the token.

Data stored in the token is transmitted to the token handling deviceusing the analog switch 156. This can be closed for a brief periodbetween the carrier interruptions. These brief closures of the switch156 will result in extra pulses appearing on the line 118 from thereceiver circuit 110 due to the consequent increase in the energyabsorbed by the token 106.

The arrangement is such that while the token handling device 100 isexpecting to receive data from the token 106, it continually transmitsdata values of zero. The token will have previously received data fromthe token handling device, and therefore its operation would have beensynchronized with the token handling device. Data transmissions from thetoken are always initiated with a start bit which is transmitted betweena clock pulse 200 and a data pulse 202. The start bit is indicated at204 in FIG. 8(b).

Further data is transmitted bit by bit in succeeding intervals betweenclock pulses 200 and data pulses 202, so that in these intervals anadditional pulse 206 may or may not appear depending upon the datacontent.

In use of the system, for reliability, any data transmission in onedirection could be followed by the same data being transmitted in theopposite direction to ensure a reliable and secure operation.

The token 106 stores in the memory 148 data such as security codes,token value, etc. When the token is first received by the token handlingdevice and powered-up by the received energy, the token and tokenhandling device communicate with each other to check security codes andthus ensure that each is suitable for use with the other. Following thisoperation, the microprocessor then transmits the token value to thetoken handling device and at the same time stores in a flag location ofthe memory 148 an indication that this sequence of operations has beencompleted.

The transmission of the carrier is then terminated, so that the token nolonger receives power. This is particularly useful in a pay phoneinstallation. At a subsequent stage when further communication with thetoken is required, the carrier is transmitted once more and the tokenpowers-up. Power-up always results in the microprocessor 142 firstchecking the flag in the memory 148. In this case, it will determinethat the preceding operations before power-down were performed totransmit the credit value to the token handling device. Accordingly, thetoken will now (after the security code checking operation has beencarried out) wait for a new token credit value to be transmitted by thetoken handling device so that it can update its stored credit value.

At the end of this procedure, the microprocessor 142 resets the flag inthe memory 148 so that when the token is subsequently released to theuser and at a later time inserted again into a token handling device andpowered-up it will behave in an appropriate manner to transmit the tokenvalue to the device.

In the above arrangement, it will be noted that the data in the token istransmitted by the connecting of a low impedance (the diode 158) acrossthe antenna 130. The diode 158 is used to prevent problems due to backEMF generated in the antenna 130, and also to ensure that the voltageswitched by the analog switch 156 is no greater than the supply voltageof that switch. It should be noted though that the alteration of theimpedance connected to the antenna 130 could be achieved in some otherfashion. In addition, the alteration of the degree of absorption of theelectromagnetic radiation could be achieved without affecting theimpedance connected to the antenna 130; for example, a separate coilcould be used for this purpose.

FIG. 6 shows in detail the receiver circuit 110 of the token handlingdevice 100. The receiving coil 108 forms part of a tuned circuit whichis coupled via an a.m. demodulating diode 160 to the inverting input ofan amplifier 162. The non-inverting input of the amplifier 162 receivesa reference potential derived from the junction between, on the onehand, a resistor 164 connected to one power supply rail, and, on theother hand, a parallel network of resistors 166 connected via respectiveanalog switches 168 to the other power supply rail. The analog switches168 are controlled by the lines 116 from the microprocessor 112.

The resistors 166 have values R 2R and 4R. It will be appreciated thatthe reference potential delivered to the non-inverting input of theamplifier 162 will vary depending upon which, if any, of the analogswitches 168 are closed. This therefore alters receiver sensitivity.

What we claim is:
 1. A token handling device which performs operationsin accordance with operational data stored in the device, and which iscapable of communicating with a token in order to determine token datastored by the token, the device being operable to enter a first mode ora second mode in dependence upon the type of operational data, thedevice being operable in the first mode to perform a said operation andin the second mode to alter the operational data in a manner dependentupon said token data.
 2. A device as claimed in claim 1, wherein theoperational data comprises a code, the device being operable in saidfirst mode to perform said operation on condition that said token dataincludes data which matches said code, and the device being operable insaid second mode to alter said code in accordance with said token data.3. A device as claimed in claim 1, wherein said operational datacomprises price data, said operation performed in said first modecomprising generating a signal permitting dispensing of a product orperforming of a service and generating a price signal indicative of thevalue of said product or service and dependent on said price data, saiddevice being operable in said second mode to alter said price data inaccordance with said token data.
 4. A device as claimed in claim 3,wherein said operation performed in said first mode comprises the stepof altering said token data in dependence on said price data.
 5. A coinoperated machine comprising:coin validating means for testing coins andgenerating signals indicative of the properties thereof; a delivery pathfor delivering coins to said coin validating means; means for generatingan output permitting the vending of a product or the performing of aservice, said means storing operational data and being operable togenerate said output in dependence on said operational data and thesignals from said coin validating means; and token reading meansoperable to receive tokens from said delivery path and to read datastored by said token, said token reading means being operable togenerate a signal dependent on said token data for altering saidoperational data.
 6. A machine as claimed in claim 5 wherein said outputgenerating means is additionally operable to generate an output independence on said token data, whereby said machine can be operated bycoins and tokens.
 7. A machine as claimed in claim 6, wherein saidmachine vends products or performs a service and wherein said tokenreading means is additionally operable to update the token data inaccordance with the value of the products vended by the machine or theservice performed by the machine, means being provided to return saidtoken to the user after the token data has been updated.
 8. A machine asclaimed in claim 5, claim 6 or claim 7, further including an accept pathand a reject path, said coin validating means being operable to generatea routing signal for determining whether items received from saiddelivery path are directed to said accept path or said reject path;saidtoken reading means being disposed along said reject path.
 9. A machineas claimed in claim 5, claim 6 or claim 7, wherein said token readingmeans is also operable in dependence upon the data stored by said tokento deliver to the token, audit data concerning operations which havebeen carried out by the machine.
 10. A coin validating and token readingdevice, said device comprising:a common path for receiving and conveyingitems including coins and tokens; coin validating means arranged toreceive items from said common path and to determine whether said itemsare genuine or non-genuine coins; a reject path and an accept path eacharranged to receive and convey items from said coin validating means;means for selectively directing items from said coin validating means tosaid accept path or said reject path in dependence on an output of saidcoin validating means; and token reading means situated in said rejectpath for reading data stored by tokens delivered from said coinvalidating means to said reject path.
 11. A device as claimed in claim10, including means responsive to the data read from said token by saidtoken reading means for selectively directing tokens leaving said tokenreading means to a first location for dispensing of the token or asecond location for storage of the token.
 12. A device as claimed inclaim 10, wherein said token reading means comprises a reading station,means for temporarily detaining tokens at the reading station, means forestabishing communication with a token detained at said reading station,and means for releasing said token so that it may be dispensed by thedevice.
 13. A device as claimed in claim 12, including means responsiveto the data read from said token by said token reading means forselectively directing tokens leaving said token reading means to a firstlocation for dispensing of the token or a second location for storage ofthe token.
 14. A device as claimed in claim 12 or claim 13, wherein saidmeans for establishing communication is operable to generate a firstsignal for powering up the token and thereafter to perform a firstcommunication sequence in which data stored by said token is read, andsubsequently to generate a second signal for powering up the token againand to perform a second communication sequence for updating the datastored by the token.
 15. A device as claimed in claim 14, wherein,during each said communication sequence, said token and said tokenreading means establish two-way communication.
 16. A device as claimedin claim 14, wherein said token comprises a non-volatile writable memorystoring flag data determining the communication sequence to be performedby the token on power up.
 17. A device as claimed in claim 10 whereinsaid token reading means is operable to generate a carrier signal, andto determine data stored by the token by detecting changes in the degreeof absorption of the carrier signal by the token.
 18. A device asclaimed in claim 14, wherein said token reading means is operable duringsaid first communication sequence to determine data stored by the tokenby detecting changes in the degree of absorption of said first signal bythe token.
 19. A device as claimed in claim 10, claim 11, claim 12 orclaim 13, including a common entrance slot through which coins andtokens can be inserted into said common path.
 20. A device as claimed inclaim 10, claim 11, claim 12 or claim 13, wherein said token readingmeans includes means for updating data stored by the token.
 21. A coinvalidating and token reading device, said device comprising first andsecond testing stations, one of said testing stations forming a coinvalidator for determining the validity of coins, and the other saidtesting station comprising means for reading data stored in a token;afirst, common path for receiving coins and tokens and for deliveringthem to said first testing station; second and third paths forselectively receiving items from said first testing station; and firstdirecting means operable in response to an output of said first testingstation for selectively directing items to said second or third path;said second testing station being disposed along said second path.
 22. Adevice as claimed in claim 21, including fourth and fifth paths forselectively receiving items from said second testing station, and seconddirecting means for selectively directing items from said second testingstation to said fourth or fifth path in response to an output of saidsecond testing station.
 23. A device as claimed in claim 21 or claim 22,including a common entrance slot through which coins and tokens can beinserted into said first path.
 24. A device as claimed in claim 21 orclaim 22, wherein said first testing station is said coin validator andsaid second testing station is said means for reading data stored in atoken.
 25. A device as claimed in claim 21 or claim 22, wherein saidtoken data reading means comprises means for detaining the token at areading station while communication between the token and the readingmeans is established.
 26. A device as claimed in claim 21 or claim 22,wherein said token data reading means is also operable to update thedata stored in the token.
 27. A data-storing token comprising:antennameans for receiving a signal generated by a token reader and forproviding an output for powering said token; a non-volatile writablememory storing flag data; control means operable to perform amulti-stage communication operation with said token reader, said tokenbeing powered-down in an interval between the stages of thecommunication operation, said control means being operable upon power-upof the token to read said flag data and in dependence on said flag datato perform either (a) a first stage of said communication operation,during the course of which said flag data is altered in a firstpredetermined manner, or (b) a second stage of said communicationoperation, during the course of which said flag data is altered in asecond predetermined manner.
 28. A token as claimed in claim 27,including switch means for altering the impedance across said antennameans under the control of said control means in order selectively toabsorb differing amounts of said output for powering said token andthereby transmit data to said token reader.
 29. A token as claimed inclaim 27 or 28, including means for detecting interruptions of saidoutput for powering said token caused by said token reader and forgenerating a data signal dependent upon the timing of saidinterruptions, whereby data can be transmitted to the token by saidtoken reader.
 30. A token as claimed in claim 29, said token beingoperable to update the data stored in said non-volatile writable memoryin accordance with data transmitted by said token reader.
 31. A coin andtoken operated machine which is operable to perform a transaction onreceipt of one or more coins or a data storing token, said machinecomprising token reading means operable to perform a multi-stagecommunication operation with the token, said token reading meanspowering-up the token during each stage of said communication operationto enable communication with said token, whereby during an initial stagethe token reading means can extract data from the token and during asubsequent stage the token reading means can send to the token updateddata for storage thereby in a non-volatile writable memory of the token,said token being powered-down between said initial and subsequentstages.
 32. A machine as claimed in claim 31, including manuallyoperable means for initiating said subsequent stage of saidcommunication operation.
 33. A machine as claimed in claim 31 or claim32, including means operable following the sending of the updated datato the token to return the token to a user.
 34. A token reading device,said device comprising:antenna means for transmitting a signal to atoken; signal generating means for generating and applying said signalto said antenna means, said signal generating means comprising means forselectively interrupting said signal at timings dependent upon data tobe transmitted to said token; and data detection means coupled to saidantenna means for detecting changes in the degree of absorption of thesignal caused by said token, thereby to detect data transmitted by thetoken.
 35. A device as claimed in claim 34, wherein said antenna meanscomprises a single coil.
 36. A device as claimed in claim 34 or claim36, wherein said signal generating means is further operable to transmitclock pulses by selectively interrupting said signal at additional,regular timings, the data transmitted to the token being synchronisedwith said clock pulses and the data detection means being operable todetect absorption changes synchronised with said clock pulses.
 37. Adevice as claimed in claim 34 or claim 35, wherein said signaltransmitted by said antenna means is sufficient to power said token. 38.A token communication system, said system comprising:token reading andwriting means including (a) antenna means for transmitting a signal to atoken, (b) signal generating means for supplying said signal to saidantenna means, (c) data transmission means for selectively interruptingsaid signal at timings dependent upon data to be sent to said token, and(d) data detection means for detecting changes in the amount by whichsaid signal is absorbed by said token and deriving data determined bythe timings at which said changes occur; and the token comprising (a)antenna means for receiving the signal transmitted by the antenna meansof said token reading and writing means, (b) power storage means forstoring power derived from the signal received by the antenna means ofsaid token, (c) data detection means for detecting interruptions of saidsignal and deriving data from the timings at which said interruptionsoccur, (d) data transmission means for selectively altering theimpedance across said token antenna means at timings dependent upon datato be transmitted to said token reading and writing means, therebyselectively to alter the amount by which said signal is absorbed by saidtoken, (e) a non-volatile writable memory, and (f) control means forderiving from said memory data for transmission by said datatransmission means of said token and for writing into said memory datadetermined by the data detected by said data detection means of saidtoken.
 39. A system as claimed in claim 38, whereih said memory storesflag data, said control means being operable to perform first and secondcommunications operations each involving the communication of data withsaid token reading and writing means in dependence upon said flag data,said control means being operable to alter said flag data in arespective predetermined manner during each said communicationoperation, whereby a different said communication operation is carriedout when the token is subsequently powered up.
 40. A system as claimedin claim 39, wherein each said communication operation involves thesending of a first code from the token to said token reading and writingmeans, and the sending of a second code from said token reading andwriting means to said token, subsequent communications being permittedonly if the first and second codes are deemed appropriate by,respectively, the token reading and writing means and the token.
 41. Acoin and token operated machine, the machine comprising:control meansfor initiating a transaction performed by the machine and having meansfor storing a credit value; coin validation means for providing, in acoin operated mode of the device, signals to said control means toincrease said credit value in response to receipt of valid coins; tokenreading and writing means, said token reading writing means comprising:(a) antenna means for transmitting a signal to a token, (b) signalgenerating means for supplying said signal to said antenna means, (c)data transmission means for selectively interrupting said signal attimings dependent upon data to be sent to said token, (d) data detectionmeans for detecting changes in the amount by which said signal isabsorbed by said token and deriving data determined by the timings atwhich said changes occur, (e) means responsive to the derived data forsupplying, in a token operated mode of the device, signals to saidcontrol means to increase said credit value; said control means beingoperable in said token operated mode to cause said token reading andwriting means to update a credit value stored in said token after saidtransaction has been performed; and means for dispensing a token whosestored credit value has been updated.
 42. A machine as claimed in claim44, wherein said antenna means comprises a single coil.
 43. A machine asclaimed in claim 41, wherein said antenna means is operable to transmita signal which is sufficient to power-up the token, said token readingand writing means thereby being operable to power-up said token during afirst communication stage in which data stored by said token is read,being thereafter operable to power-down said token, and beingsubsequently operable to power-up the token in a second communicationsequence in order to update the data stored by said token.
 44. A machineas claimed in claim 41, claim 42 or claim 43, comprising manuallyoperable means for initiating the updating of the data stored by saidtoken and the dispensing of said token to a user.
 45. A machine asclaimed in claim 43, wherein each said communication stage involves thesending of a first code from the token to said token reading and writingmeans, and the sending of a second code from said token reading andwriting means to said token, subsequent communications being permittedonly if the first and second codes are deemed appropriate by,respectively, the token reading and writing means and the token.